Arnold not rendering image plane behind object w/ transmission

[mikehalak007]

Hi all,

I'm seeing an issue with shader transmission, image planes, and rendering while using Maya 2018 + Arnold MotA 3.1.2.1.

Specifically I have an image plane placed behind a transparent object; the background image appears through the transparent object in the viewport, but does not render in Arnold. 

This is clearer in the screen capture, showing the viewport at left, shader attributes in the center, and Arnold render on the right. Please note the transparent wine glasses obscuring the background at right.

I've checked: 

Shader / ai standard surface settings: 

- transmission weight set to '1' 

Geometry object:

 - Arnold 'opaque' is unchecked

Image plane settings:

- visible in reflections

- visible in refractions

Render settings:

-Ray depth (in render settings)

The most recent info I've found at https://forums.autodesk.com/t5/maya-shading-lighting-and/arnold-5-image-plane-render-problems/td-p/7... does not seem to resolve or suggest a specific workaround...

Are people still encountering this issue–is there a solve? Many thanks:) 

[Stephen.Blair · Accepted solution]

The image plane (aka the background) is not visible to transmission rays. It's visible to camera rays only.

Even if it was visible to transmission rays, the image plane object is effectively infinitely far away, so there would be not actual refraction.

If you want something that's visible to transmission rays (or any other ray besides camera rays), you'll need to add an object in the scene as a backdrop.

[mikehalak007]

Thanks Stephan, I'll take the 'image-object backstop' approach for a spin. Cheers

[yessben59]

I have the same problem , background does not appear behind transmission as you see in picture

however , I do not have this problem in another  project it appear correctly but I did not understand how I had done

give me the solution with most detail and thank you